Liquid Ring Pump Impeller With Conical Hub for Compact Air Handling
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Solution Overview
Problem
Rotary wing aircraft fuel pumps face challenges in suctioning fuel at low pressures due to gravity and inertial forces, and must handle air bubbles effectively, while existing liquid ring pumps suffer from non-symmetrical flow patterns and envelope constraints that limit air pumping and suction performance.
Innovation Solution
A liquid ring pump design featuring a conical central hub and radially extending main vanes, with a reinforcing ring and secondary vanes, allows for improved air bubble prevention and enhanced suction performance by creating a pressure gradient that directs air bubbles towards the discharge port, and incorporates a side channel impeller housing with co-located inlet and discharge ports to reduce overall size and enhance air handling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a typical impeller with non-symmetrical flow pattern is used, then the pump can be designed with co-located inlet and discharge ports on one side, but air bubbles collect on the impeller hub and expand in the seal zone, limiting air pumping and suction performance
Solution Approach 1:
The patent applies asymmetry by positioning the discharge port offset from the impeller hub rather than symmetrically at the periphery. This asymmetric discharge port location prevents air bubbles from collecting on the hub and being carried through the seal zone, while still allowing co-located inlet and discharge ports on one side of the impeller, thus resolving the contradiction between compact envelope size and air pumping performance
2Volume of moving object
If a typical impeller with non-symmetrical flow pattern is used, then the pump can be designed with co-located inlet and discharge ports on one side, but suction performance is limited due to air bubble expansion in the seal zone
Solution Approach 1:
The asymmetric discharge port location prevents air bubbles from expanding in the seal zone during the suction phase, maintaining reliable suction performance even with the compact co-located port configuration
3Productivity
If the discharge port is located near the hub away from the liquid ring, then air bubbles can be compressed, but non-symmetrical flow pattern causes air bubbles to collect on the impeller hub
Solution Approach 1:
The patent intentionally uses asymmetric flow pattern with offset discharge port location to achieve beneficial air compression while preventing harmful air bubble collection on the hub, transforming the asymmetry from a problem into a solution
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The design enhances air pumping and suction capabilities, preventing air bubbles from collecting on the impeller hub and improving fuel suction performance, even at low pressures, while reducing the pump's envelope size for aircraft applications.
Implementation Method 1
The conical shape of the outer surface of the central hub creates a pressure drop across the outer surface to assist in preventing air bubbles from attaching to the central hub
Implementation Method 2
When pumping air in a liquid ring pump, centrifugal forces separate the fuel and air (or vapor during low suction pressure conditions). The heavier fuel particles are flung to the outer diameter while the air bubbles collect near the impeller hub
Data Source
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AI summary
A liquid ring pump is provided. The liquid ring pump is designed to reduce the overall envelop of the ring pump. The liquid ring pump includes a housing and an impeller. The housing defines an impeller cavity. The impeller cavity has an inlet port and a discharge port. The impeller is positioned within the impeller cavity for rotation about a central rotational axis. The impeller includes a central hub defining a conical outer surface and a plurality of angularly spaced apart main vanes extending radially outward from the conical outer surface relative to the central rotational axis. The inlet and discharge ports may be located on a same side of the impeller housing.